Journal of neural transmission. General section最新文献

{"title":"Cyclic GMP generation mediated by 5-HT-2 receptors via nitric oxide-dependent pathway and its effect on the desensitization of 5-HT-2 receptors in C6 glioma cells.","authors":"A Kagaya,&nbsp;N Motohashi,&nbsp;A Kugaya,&nbsp;T Yamaji,&nbsp;T Hayashi,&nbsp;Y Okamoto,&nbsp;H Shinno,&nbsp;M Takebayashi,&nbsp;Y Uchitomi,&nbsp;S Yamawaki","doi":"10.1007/BF01276863","DOIUrl":"https://doi.org/10.1007/BF01276863","url":null,"abstract":"<p><p>Serotonin (5-HT)-2 receptor-mediated cGMP generation was investigated in comparison with calcium (Ca2+) mobilization in C6 glioma cells. 5-HT enhanced cGMP generation, and risperidone and ketanserin potently blocked the response. These results indicate that 5-HT-2 receptors are responsible for the cGMP generation. 5-HT-induced cGMP production was completely abolished by BAPTA, an intracellular Ca2+ chelating agent, or NG-mono-methyl-L-arginine(NMMA), a nitric oxide synthase (NOS) inhibitor, suggesting that 5-HT-induced cGMP generation was through nitric oxide (NO)-dependent pathway. 5-HT (10 microM)-elicited Ca2+ mobilization and cGMP generation were reduced to 40 and 15% after pretreatment with 10 microM 5-HT for 4 hours. NMMA did not modify 5-HT-induced desensitization of either Ca2+ mobilization or cGMP generation, suggesting that NO pathway is independent of the desensitization. The present study has demonstrated the nature of 5-HT-2 receptor-mediated cGMP generation in C6 glioma cells.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"100 1","pages":"27-38"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01276863","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19721618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation of extracellular amino acids in striatum of freely moving rats by in vivo microdialysis.","authors":"J Semba,&nbsp;S Kito,&nbsp;M Toru","doi":"10.1007/BF01276864","DOIUrl":"https://doi.org/10.1007/BF01276864","url":null,"abstract":"<p><p>To investigate the characteristics of extracellular amino acids released from the striatum, we performed in vivo microdialysis in non-anaesthetised, freely moving rats. Amino acids were determined after precolumn derivatisation with o-phthalaldehyde by high-performance liquid chromatography and fluorescence detection. The omission of Ca2+ in the perfusion medium partially decreased the basal concentration of aspartate and glutamate. This shows that a small fraction of basal concentration of aspartate and glutamate is of neuronal origin. The effect of high K+ and veratrine stimulation was evaluated in the presence or absence of Ca2+ or tetrodotoxin (1 microM). High K+ and veratrine caused a remarkable increase in the aspartate and glutamate efflux. The omission of Ca2+ only partially decreased K(+)-stimulated aspartate and glutamate efflux. Tetrodotoxin completely antagonised veratrine-stimulated aspartate and glutamate efflux. Although glycine and taurine releases were stimulated by high K+ and veratrine, their release was not always antagonised with Ca2+ omission or tetrodotoxin inclusion. Thus, the neuronal origin of stimulated release of glycine and taurine is unclear. Although tetrodotoxin sensitivity and Ca2(+)-dependency are regarded as a basic criterion for classical neurotransmitters in microdialysis experiments, they should not be adapted to the physiological characteristics of the release of amino acids.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"100 1","pages":"39-52"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01276864","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19721619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin on the dopaminergic and cholinergic receptors as evaluated by positron emission tomography in the Rhesus monkey.","authors":"Y Tani, T Ishihara, T Kanai, T Ohno, J Andersson, A Lilja, G Antoni, K J Fasth, P Bjurling, G Westerberg","doi":"10.1007/BF01281154","DOIUrl":"10.1007/BF01281154","url":null,"abstract":"<p><p>The effects of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) on the central cholinergic and dopaminergic systems in the Rhesus monkey brain were investigated by positron emission tomography (PET) with the muscarinic cholinergic receptor ligands (N-[11C]methyl-benztropine) and dopaminergic receptor ligands selective for D1, D2, and D3 subtypes ([11C]SCH23390, N-[11C]methyl-spiperone, and (+)[11C]UH232, respectively). None of the doses (3, 10, and 30 mg/kg i.v.) of R-THBP used significantly affected the regional cerebral blood flow (rCBF as determined by Raichle's H(2)15O method), and 10 mg/kg of R-THBP had little effect on the regional cerebral metabolic rate of glucose (rCMRglc) in the Rhesus monkey brain, as assessed by the graphical [18F]fluoro-deoxyglucose method. The effect of R-THBP on the muscarinic cholinergic system was dose dependent; while 3 mg/kg of R-THBP did not significantly alter the uptake ratio of N-[11C]methylbenztropine in several brain regions to that in the cerebellum, 10 and 30 mg/kg of R-THBP significantly reduced the uptake ratio in the thalamus, as well as in the frontal and temporal cortices. None of the doses (3, 10, and 30 mg/kg i.v.) of R-THBP tested affected [11C]SCH23390 (dopamine D1 receptor) binding. However, the k3 value for N-[11C]methyl-spiperone (dopamine D2 receptor) binding, which represents the association rate X Bmax value, was significantly decreased in the striatum. The uptake ratio of (+)[11C]UH232 (dopamine D3 receptor) in the striatum to that in the cerebellum was also decreased by administration of R-THBP (3 and 30 mg/kg i.v.). These findings suggest that R-THBP acts on dopamine D2 and D3 receptors selectively without markedly affecting dopamine D1 receptor binding. Furthermore, the changes in cholinergic and dopamine D2 and D3 receptors in vivo can not be attributed to a change in rCBF but may depend on the action of R-THBP.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"102 3","pages":"189-208"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01281154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19758954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of maternal melatonin on melatonin receptors in rat offspring.","authors":"M Zitouni,&nbsp;M Masson-Pévet,&nbsp;F Gauer,&nbsp;P Pévet","doi":"10.1007/BF01271534","DOIUrl":"https://doi.org/10.1007/BF01271534","url":null,"abstract":"<p><p>Using quantitative autoradiography, we have studied the influence of maternal plasma melatonin on the expression and density of melatonin receptors in the brain and pituitary of rat offspring. At birth, the same structures displayed melatonin receptors whether the rats were born to and reared by intact or pinealectomized dams. The receptor density was, however, about 20% lower in the group born to pinealectomized dams. At postnatal day 9, when the pups of both groups synthetize rhythmically their own melatonin, this difference was suppressed. These results indicate that melatonin does not appear to be a requirement for the expression of its receptors, but seems to play a stimulatory role in their synthesis.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"100 2","pages":"111-22"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271534","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19924822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MPP+ selectively affects calcium homeostasis in mesencephalic cell cultures from embryonal C57/Bl6 mice.","authors":"T S Chen,&nbsp;E Koutsilieri,&nbsp;W D Rausch","doi":"10.1007/BF01271538","DOIUrl":"https://doi.org/10.1007/BF01271538","url":null,"abstract":"<p><p>1-Methyl-4-phenylpyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) serves as a valuable tool in animal models of Parkinson's disease. Primary cell cultures of mesencephalon from C57/Bl6 mice were used to investigate the effects of various dopaminergic neurotoxins on the intracellular calcium metabolism. MPP+ was compared to its precursor MPTP and a structural analogue paraquat (methylviologen). Direct addition of these neurotoxins (10 microM) to fura-2-labeled cells did not change intracellular calcium concentrations in the presence of 1 mM extracellular calcium. When mesencephalic neurons were exposed to the compounds for 24 hours, only MPP+ led to an increase in calcium concentration in the absence and presence of extracellular calcium (36%, p < 0.05 and 47%, p < 0.01 versus control group). Intracellular calcium concentrations in cortical cultures devoid of dopaminergic cells were not changed by the above neurotoxins. Thus MPP+ is shown to selectively increase intracellular calcium concentrations in mesencephalic cultures.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"100 2","pages":"153-63"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271538","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19925389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some considerations on estimating event-related brain signals.","authors":"S Krieger,&nbsp;J Timmer,&nbsp;S Lis,&nbsp;H M Olbrich","doi":"10.1007/BF01271473","DOIUrl":"https://doi.org/10.1007/BF01271473","url":null,"abstract":"<p><p>Understanding the timing of mental acts is one of the prominent questions in information processing research. The analysis of event related potentials (ERP) with their high temporal resolution might make access to cognition related brain activity possible. We consider three major problems which make the application of ERPs questionable and then propose some solutions to these problems. The primary problem concerns the separation of the ERPs from the background EEG which is not related to the stimulus. The most common method used is averaging. We argue that this is not the most appropriate method and suggest an alternative for estimating the signal in single-trial recordings. Artifacts present a second problem. We will first review established methods of dealing with eye-movement artifacts and then propose an alternative. We will also report on current work on the parametrisation of single-trial signal estimates, which constitute the third problem considered.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"99 1-3","pages":"103-29"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271473","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19559357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced frontal and occipital lobe asymmetry on the CT-scans of schizophrenic patients. Its specificity and clinical significance.","authors":"P Falkai,&nbsp;T Schneider,&nbsp;B Greve,&nbsp;E Klieser,&nbsp;B Bogerts","doi":"10.1007/BF01271470","DOIUrl":"https://doi.org/10.1007/BF01271470","url":null,"abstract":"<p><p>Frontal and occipital lobe width were determined in the computed tomographic (= CT) scans of 135 schizophrenic patients, 158 neuropsychiatrically healthy and 102 psychiatric control subjects, including patients with affective psychosis, neurosis and schizoaffective psychosis. Most healthy right handed subjects demonstrate a relative enlargement of the right frontal as well as left occipital lobe compared to the opposite hemisphere. These normal frontal and occipital lobe asymmetries were selectively reduced in schizophrenics (f.: 5%, p < .0005; o.: 3%, p < .05), irrespective of the psychopathological subgroup. Schizophrenic neuroleptic non-responders revealed a significant reduction of frontal lobe asymmetry (3%, p < .05), while no correlation between BPRS-subscores and disturbed cerebral laterality could be detected. In sum the present study demonstrates disturbed cerebral lateralisation in schizophrenic patients supporting the hypothesis of interrupted early brain development in schizophrenia.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"99 1-3","pages":"63-77"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271470","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19559288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavioural and neurochemical interactions of the AMPA antagonist GYKI 52466 and the non-competitive NMDA antagonist dizocilpine in rats.","authors":"M Bubser,&nbsp;T Tzschentke,&nbsp;W Hauber","doi":"10.1007/BF01271550","DOIUrl":"https://doi.org/10.1007/BF01271550","url":null,"abstract":"<p><p>The behavioural and neurochemical effects of the N-methyl-D-aspartate (NMDA) antagonist dizocilpine and the alpha-amino-3-hydroxy-5-methylisoxazole- 4-propionic acid (AMPA) antagonist GYKI 52466, given alone or in combination, were investigated in rats. Locomotor activity was increased by dizocilpine (0.2 mg/kg), but not by GYKI 52466 (2.4 mg/kg). Dizocilpine-induced hyperlocomotion was reduced by co-administration of GYKI 52466. In dizocilpine-treated rats dopamine (DA) metabolism (measured as DOPAC [dihydroxyphenylacetic acid] or DOPAC/DA in post mortem brain tissue) was increased in the prefrontal cortex and nucleus accumbens. In GYKI 52466-treated rats serotonin was reduced in the prefrontal cortex and nucleus accumbens while DA metabolism was not affected. In rats treated with dizocilpine plus GYKI 52466, DA metabolism was increased only in the prefrontal cortex, but not in the nucleus accumbens, when compared with vehicle-treated animals. These data confirm that AMPA and NMDA antagonists do not have synergistic effects on locomotor activity. A differential role of NMDA and AMPA antagonists in the control of mesolimbic DA neurons will be discussed here.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"101 1-3","pages":"115-26"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271550","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19669005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of dopamine D3 preferring compounds on conditioned place preference and intracranial self-stimulation in the rat.","authors":"T Kling-Petersen,&nbsp;E Ljung,&nbsp;L Wollter,&nbsp;K Svensson","doi":"10.1007/BF01271543","DOIUrl":"https://doi.org/10.1007/BF01271543","url":null,"abstract":"<p><p>Compounds showing an in vitro binding preference for the dopamine D3 receptor were tested in two models designed to assess positive reinforcement in the rat: intracranial self-stimulation (ICSS) and conditioned place preference (CPP). R-(+)-7-OH-DPAT, a D3 preferring agonist, inhibited ICSS behaviour over a wide dose range. At higher doses, a facilitation of ICSS was seen. In the CPP model, 7-OH-DPAT was inactive except at the highest dose where a significant change in preference was seen. A dose of R-(+)-7-OH-DPAT, that significantly inhibited ICSS behaviour, was combined with a dose of d-amphetamine, that significantly facilitated ICSS behaviour. Surprisingly, this resulted in a significant synergistic facilitation of the amphetamine response. The putative D3 antagonist, U99194A was inactive in the ICSS model but induced significant place preference. The present results suggest that the dopamine D3 receptor, in contrast to the D2 receptor, has an inhibitory influence on reward mechanisms.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"101 1-3","pages":"27-39"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271543","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19669639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of aging on lazabemide binding, monoamine oxidase activity and monoamine metabolites in human frontal cortex.","authors":"M D Galva,&nbsp;G P Bondiolotti,&nbsp;M Olasmaa,&nbsp;G B Picotti","doi":"10.1007/BF01271547","DOIUrl":"https://doi.org/10.1007/BF01271547","url":null,"abstract":"<p><p>Age-related modifications of monoamine oxidase-A and -B (MAO-A and MAO-B) and amine metabolite concentrations were studied in human frontal cortex taken postmortem from 22 subjects of various ages (21-75 years). Qualitative and quantitative analysis for MAO-B was provided by kinetic studies with a specific radioligand, [3H]lazabemide. The data demonstrated a significant (P < 0.05) positive correlation between the density of [3H]lazabemide binding sites (Bmax) and age of the subject, without showing an apparent modification in the dissociation constant (KD) of the radioligand. In parallel experiments, MAO-B but not MAO-A activity was shown to correlate with age (P < 0.05). The concentrations of the amine metabolites 4-hydroxy-3-methoxyphenylacetic acid (HVA), 5-hydroxyindole-3-acetic acid (5-HIAA), 3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenylglycol (MHPG) and 3,4-dihydroxyphenylglycol (DHPG) were all devoid of a correlation with age. Neither did the concentrations of these metabolites relate to the respective subject's MAO-B enzymatic activity nor to [3H]lazabemide Bmax. A correlation, though rather weak, was obtained between MAO-A activity and MHPG concentration (P = 0.045). The MAO-A and -B enzyme characteristics in subjects who had committed suicide (n = 9) did not differ from those of subjects deceased for other causes (n = 13). Among the measured monoamine metabolites the concentrations of DOPAC and HVA were higher in the suicide versus control group (P < 0.05). The present data confirm in a direct manner that the increase in MAO-B activity in aging brain is due to an enhancement of the number of active sites of the enzyme and not through modifications of its kinetic characteristics. Furthermore, that neither the characteristics nor the activity of the enzyme are changed in the frontal cortex of suicide victims compared to control subjects.</p>","PeriodicalId":77215,"journal":{"name":"Journal of neural transmission. General section","volume":"101 1-3","pages":"83-94"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01271547","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19670334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}